The FEC document is, specifically, a record of its decision not to sanction the Trump campaign for conduct related to the apparent transaction. A complaint filed by an activist group that supported Hillary Clinton had alleged that the Trump camp had violated reporting laws related to payments for the actors; the FEC concluded that no significant violation had occurred because the campaign later disclosed a payment to a contractor (Gotham Government Relations) that subcontracted with Extra Mile. But in the course of explaining why it would not discipline the campaign, the FEC concludes that some announcement attendees were, in fact, paid to be there:

In this matter, the available information indicates that the [Trump campaign] retained Gotham as an event consultant, and Gotham, in turn, subcontracted with Extra Mile to provide extra administrative support at Trump’s announcement, including the provision of at least some of the rally crowd.